As mining conditions continue to deteriorate due to depletion of easily accessible reserves, lateral pressure on mine ribs is becoming the rule, rather than the exception. In order to protect miners from rib rolls and rib burst conditions, it is an object of the present invention to provide a yielding positive anchoring rib support which allows for increasing resistance as rib convergence progresses.
Currently, the two major rib support methods being employed are ordinary timber posts with boards set on the in by side near the rib. The second method of rib support is installing a resin anchor bolt in the rib. The negative points with timber supports are the posts dislodge easily when horizontal load is applied due to the fact that they are anchored only by wooden wedges, and the transport of the timber to the installation site requires a machine due to the significant weight of the timber posts. The installation of anchor bolts in the rib requires a drilling machine and the drilling process increases the instability of the rib.
Another object of the present invention is to provide the miner with flexibility in regard to the installation process wherein the support is lightweight enough to be carried by one person and requires no special tools or equipment for installation.
The mine rib support device disclosed in U.S. Pat. No. 7,490,440, discloses a mine rib support which does alleviate some of the problems incurred with the prior art methods, however, this prior art support requires inclusion of an expensive jacking mechanism being included as an integral part of each support device. The upper and lower members of the support of this prior art reference are separated by the jacking mechanism which further decreases the amount of horizontal resistance that the support can provide. It is another object of the present invention to also eliminate these disadvantages.